A 50-sqm lake has been discovered under Trastevere train station in the Monteverde district of Rome, according to the blog of the local branch of political party Sinistra, Ecologia, Libertà (SEL).

The discovery came about during an inspection of the enormous brown tufa quarries found recently under the intersection of Viale Trastevere and the Circonvallazione Gianicolense.

In recent months large holes have opened up in the area, prompting authorities to investigate what lies beneath.

The blog states that other vast tufa quarries in Monteverde were also "rediscovered" in October and are in the process of being explored.